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ROS与QT语言入门教程-显示ROS发布的视频消息

ROS与QT语言入门教程-显示ROS发布的视频消息

说明

  • 实现显示ROS发布的视频消息

点击查看完整代码

确定PC端的USB摄像头的正常使用

roslaunch usb_cam usb_cam-test.launch

步骤

  • 创建ROS-QT-GUI模板 mul_t
catkin_create_qt_pkg mul_t
  • 修改界面gui

main_window.ui文件:拖入一个标签控件,将对象名改为label_camera

  • 修改main_window.hpp
#include <QtGui/QMainWindow>
#include "ui_main_window.h"
#include "qnode.hpp"
#include <QImage>
#include <QMutex>
namespace mul_t {
class MainWindow : public QMainWindow {
Q_OBJECT
...
public Q_SLOTS:
...
    void updateLogcamera();
    void displayCamera(const QImage& image);
private:
  Ui::MainWindowDesign ui;
  QNode qnode;
  QImage qimage_;
  mutable QMutex qimage_mutex_;
};
}  // namespace mul_t
#endif // mul_t_MAIN_WINDOW_H
  • 修改qnode.hpp文件
   //添加头文件
    #include <opencv2/core/core.hpp>
    #include <opencv2/highgui/highgui.hpp>
    #include <opencv2/imgproc/imgproc.hpp>


 #include <image_transport/image_transport.h>
    #include <cv_bridge/cv_bridge.h>
    #include <QImage>
    ...
    public:
void myCallback_img(const sensor_msgs::ImageConstPtr& msg);//camera callback     function
  QImage image;
  Q_SIGNALS:
      void loggingCamera();//发出设置相机图片信号
    private:
      int init_argc;
      char** init_argv;
          ros::Publisher chatter_publisher;
      QStringListModel logging_model;
      image_transport::Subscriber image_sub;
 cv::Mat img;

修改main_window.cpp

    /*********************
** Logging
**********************/
 QObject::connect(&qnode,SIGNAL(loggingCamera()),this,SLOT(updateLogcamera()));

void MainWindow::displayCamera(const QImage &image)
{
    qimage_mutex_.lock();
    qimage_ = image.copy();
    ui.label_camera->setPixmap(QPixmap::fromImage(qimage_));
    ui.label_camera->resize(ui.label_camera->pixmap()->size());
    qimage_mutex_.unlock();
}
void MainWindow::updateLogcamera()
{
  displayCamera(qnode.image);
}
  • 修改qnode.cpp:
#include "sensor_msgs/image_encodings.h"
void QNode::myCallback_img(const sensor_msgs::ImageConstPtr &msg)
{
    try
    {
        cv_bridge::CvImageConstPtr cv_ptr = cv_bridge::toCvShare(msg, sensor_msgs::image_encodings::RGB8);
        img = cv_ptr->image;
        image = QImage(img.data,img.cols,img.rows,img.step[0],QImage::Format_RGB888);//change  to QImage format
        ROS_INFO("I'm setting picture in mul_t callback function!");
        Q_EMIT loggingCamera();
    }
    catch (cv_bridge::Exception& e)
    {
        ROS_ERROR("Could not convert from '%s' to 'bgr8'.", msg->encoding.c_str());
    }
}

运行

  • 启动相机
rosrun usb_cam usb_cam_node
  • 执行qt程序

参考资料

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标签: ros与qt语言入门教程, ros qt